1. Field of the Invention
This invention relates to a rowing machine which simulates the actual water resistance encountered by a rower while the entire machine remains stationary. Particularly, the invention relates to a rowing machine in which a pair of generally oblong water-filled tanks are placed on side of a rowing attachment which can be mounted between the two tanks either on the ground or on a boat within a third tank.
2. Description of the Prior Art
A so-called "rowing-tank" in which rowing club members on college rowing teams practice in the off season and in which beginners can learn the sport is often provided in indoor training facilities. This tank consists of a shallow indoor pool just large enough to accommodate a race-boat permanently anchored at one edge of the pool. The athletes train in the generally rectangular tank on one side of the boat at a time. Because of the currents generated during the rowing motion and the closed rectangular shape of the pool, water resistance in this situation is substantial. It has been found to be necessary to form the oar blades with several large holes or slots (3-4 inches in diameter) in order to reduce the water resistance and simulate the actual water resistance which would be encountered in a river or a lake.
There has been a long-felt need for a rowing machine which can more closely simulate the actual water-resistance encountered in competitive rowing conditions and which can be utilized in an indoor training facility as when the weather does not permit training under actual conditions. The rowing machine of the present invention provides three independent, shallow tanks or pools with 12-15 inches of water next to each other, with the middle tank being just large enough to accommodate a row boat having a rowing attachment thereon. Fore and aft ends of the boat are secured to the corresponding ends of the middle pool with elements such as turnbuckles or springs. The size, spacing and shape of the outer pools is determined so that the blades of the oars can make a full stroke without touching the outer side walls of these pools. Normally, the oars travel about two to three inches from the tank outer walls.
It can be seen that while the rowing attachment can be mounted in a boat in an independent tank, it can also be mounted on the ground between the two generally oblong water-filled outer tanks. Also, the rowing machine may be placed in or above a single pool with oval or oblong partitions extending downward from just above the surface to a predetermined distance below the water surface. The depth of extension of the walls of the oval partition is sufficient to produce the desired flow pattern. The oval or oblong partitions may or may not have a bottom thereto. In any case, the rowing attachment utilizes a standard sliding seat arrangement as is used on competitive sculls and in other rowing boats and machines. The shape of the outer walls of the two outer tanks when utilizing a rowing attachment having only one moving seat are oval, with the longitudinal axis of each tank parallel to the axis of the boat or rowing attachment. If two or more sliding seats are utilized, then the sides of the oblong outer tanks should be straight with round or semicircular ends.
In order to ensure proper circulation within each generally oblong outer tank, the ends thereof are provided with flow diverters having covers and a plurality of plates extending from the bottom of the pool at predetermined intervals to the cover. These flow diverters include a dividing wall and have, usually at both ends of the generally oblong tanks, a sandwich-like structure composed of generally horizontal semicircular plates. The inner diameter of the semicircle is angled with respect to the longitudinal axis of each water-filled tank such that the oars are given more room along the outer walls of the tank than on the inner walls.
When rowing starts, the water slowly begins circulating in the tanks, and the faster the circulation, the easier the oar strokes become. Full circulation can be reached in two to three minutes and after that period of time, the rowers experience the same resistance as they would experience with a boat in free water. This eliminates the necessity of making holes in the blades of the oars.
It can be seen that in the left hand oblong tank, the circulation of the water will be clockwise with respect to the rower, and in the right hand tank the circulation of the water will be counterclockwise. To ensure that there is no mixing of the flows within the generally oblong outer tanks, a divider wall or plate is placed in the middle of each tank along the longitudinal axis thereof to help keep the water circulating properly.
People who learn rowing with the present invention can participate in what is the healthiest, most entertaining, most aerobic outdoor sport. All this can be done indoors or outdoors. The tanks of the rowing machine of the present invention can be built for any length of boat and any number or rowers. A simpler and less expensive way to build the apparatus is by placing the rowing attachment having the sliding seats on the ground between the oblong outer tanks rather than in the boat in the third or middle tank.